Aim: To investigate the effects of the water-based exercise on balance, mobility, mobility and functional independence, functional performance, fear of falling and quality of life in people with Parkinson’s disease. Methods: We searched pubmed/MEDLINE, Cochrane Central Register of Controlled Trials, PEDro data base and SciELO to June 2020 for randomised controlled trials that investigated the effects of water-based exercise in people with Parkinson’s disease. Two comparisons were made: water-based exercise versus usual care and water-based exercise versus land-exercise. The main outcomes were Balance, Confidence, Mobility, Unified Parkinson’s Disease Rating Scale and quality of life. Mean differences (MD) with 95% confidence interval (CI) were calculated, and heterogeneity was assessed using the I2 test. Results: Fifteen randomised controlled trials were found (435 people). Compared to usual care, water-based exercise resulted in improvement in balance MD (9.1, 95% CI: 6.5, 11.8, N = 45). Water-based exercise resulted in improvement in balance MD (3.1, 95% CI: 1.2, 5.0, N = 179), mobility MD (−2.2, 95% CI: −3.3, −1.0, N = 197) and quality of life MD (−5.5, 95% CI: −11, −0.07, N = 98) compared to land-based exercise, but without significant difference in functional performance MD (0.01, 95% CI: −2.6 to 2.7, N = 69). Land-based exercise resulted in improvement in fear of falling MD (−3.5, 95% CI: −5.6, −1.3, N = 58) compared to water-based exercise. Conclusion: Water-based exercise was more efficient than land-based exercise and/or usual care in improving balance, mobility and quality of life in people with Parkinson’s disease.